Generally, a distribution panel has a structure in which a plurality of busbars, which is electrically connected with a load terminal of, e.g., a three-phase 200V main breaker connected with a power supply, is connected with a power supply terminal of a branch breaker, so that electricity of, e.g., a single-phase 200V power is supplied to an electric device such as a magnet conductor serving as a load.
Conventionally, there has been known a configuration of a distribution panel in which a branch breaker having a plug terminal metal fitting capable of electrically connecting with busbars is installed therein. Further, the branch breaker and an adapter having a clip-type plug terminal metal fitting capable of electrically connecting with the busbars are screw-coupled to the distribution panel via a mounting base (see, for example, Patent Document 1).
Further, there has been known another configuration of a distribution panel in which a mounting base installed in the distribution panel is screw-coupled with a breaker mount where a branch breaker electrically connected with busbars is mounted, so that the branch breaker is fixed to the distribution panel (see, for example, Patent Documents 2 and 3).    Patent Document 1: Japanese Patent Laid-open Publication No. 2008-61455 (FIGS. 1, 12 and 14)    Patent Document 2: Japanese Patent Laid-open Publication No. 2008-109808 (FIGS. 1, 4, 5 and 6)    Patent Document 3: Japanese Patent Laid-open Publication No. 2008-109809 (FIGS. 1, 4, 5 and 6)